Has Anyone tried a Small storage heater on a boat?

[Quaysider]

I suspect you'e joking there but it did occur to me to pipe some heat through the flooring - I saw a vid of a chap on you tube a while ago that had done just that.... he claimed it made a major difference but i don't like he idea of additional piping under the floor...

 

It was only a thought and i guess had it actually been a useful and practical idea, someone else would already have been doing it.

[kevinl]

Something I've seen done that does work was the 2 walls beside the fire were lined with thermal breeze block. When the fire was lit they soak up the heat and as it dies down they release the stored heat. OK there's no control over them but it's as near free heat as you can get, maintenance free and only costs a few quid to do ,I think he used 10 or 12 of them then tiled over the top, no doubt it does work and costs under £20 to do. I guess you could buy one (only £1.39) heat it in the oven then see how long it holds heat for. Although latent heat isn't free it's as near as it gets.

K

[Nitrowing]

I was thinking along the same lines as ditchcrawler. My ballast is a freezing cold collection of cast iron weights (so cold, in fact, I was considering keeping the milk in there!). Running a copper pipe along the skirting of the interior to a radiator sunk in amongst the ballast shouldn't be too difficult?

http://www.screwfix.com/p/pvc-coated-copper-pipe-white-10mm-x-25m/34388

[MtB]

lol I know that but it would be "cost effective" give the engine would be running anyway and the solar panels doing their bit. I'll have to bow to everyone's experience in life afloat though and concede it's probably not worth the effort .... perhaps I'll pepper the entire boat with solar cells and then have a try ;-)

 

 

The energy from a running engine comes from the fuel you buy so if you load up the alternator to charge the storage heater, you'll use proportionally more diesel. So it is not 'free energy'.

 

The solar heat IS free, but in my experience solar panel output drops by about 90% in deep mid winter. Note drops by, not drops to, so you can pretty well rule out the solar panels having spare energy for space heating in mid December.

 

Others will say I'm wrong about the solar but this is my personal experience with my own two solar installations.

 

MtB

I don't know what the efficiency of a NSH is but it's not great

 

I can help you there. The efficiency of a storage heater is 100%.

 

If you disagree, can you outline where the losses occur?!

 

MtB

[nicknorman]

Thermostatic electric underblanket of the type you can leave on all night at a low setting. Keeps you toasty warm and uses surprisingly little battery power. No point in heating the whole room when you just need to heat the bed. Best thing we bought for winter boating!

[Guest]

 

 

The energy from a running engine comes from the fuel you buy so if you load up the alternator to charge the storage heater, you'll use proportionally more diesel. So it is not 'free energy'.

 

The solar heat IS free, but in my experience solar panel output drops by about 90% in deep mid winter. Note drops by, not drops to, so you can pretty well rule out the solar panels having spare energy for space heating in mid December.

 

Others will say I'm wrong about the solar but this is my personal experience with my own two solar installations.

 

MtB

 

I can help you there. The efficiency of a storage heater is 100%.

 

If you disagree, can you outline where the losses occur?!

 

MtB

Interesting argument re. efficiency. The electricity board where I once worked used to use the sales pitch that storage heaters are 100% efficient. What energy goes in comes out. With electric heating the losses mostly occur at the power station (which the consumer pays for one way or another.). In a boat situation, the energy losses would largely be at the engine which drives the genny. But I believe you are right about the heater.

[John Williamson 1955]

Running a heater off the average boat electrical system won't be cheap. Given the average engine specific fuel consumption of 2.5 to 3 kilowatt hours per litre, and the average alternator - battery - inverter chain efficiency of about 50%, that's going to cost about 60p per unit, so fully charging a storage heater that will store 6 kilowatt hours would cost (Very rounded) about £3.

 

If the heater element is 850 watts, it would take 7 hours to get the core hot, so unless you're cruising all day,it will never get warm enough.

[Guest]

Running a heater off the average boat electrical system won't be cheap. Given the average engine specific fuel consumption of 2.5 to 3 kilowatt hours per litre, and the average alternator - battery - inverter chain efficiency of about 50%, that's going to cost about 60p per unit, so fully charging a storage heater that will store 6 kilowatt hours would cost (Very rounded) about £3.

 

If the heater element is 850 watts, it would take 7 hours to get the core hot, so unless you're cruising all day,it will never get warm enough.

I tend to agree. Even in a domestic situation and buying electricity from the grid, if storage heaters were used at the normal "day" rate, they would be very expensive to run. I can't speak for today, but the main difference that made storage heaters affordable in the home, was the economy 7 electricity rate, which made overnight charging of such heaters (and other electrical appliances) considerably cheaper. We used to run our washing machine/tumble drier in the night to take advantage of the reduced rate.

[Kae]

Personally I'd use a heat exchanger in the skin tank cooling circuit for the engine to garner "free" heating whilst the engine is running (this is genuinely free heat, as otherwise it just goes to warm up the canal!). This won't adversely affect the engine, as the thermostat will only allow heat to flow as requried to cool the engine.

 

This does require a heating circuit, but as you'll likely have a secondary source of heating anyway, you can join it with the diesel/gas heater and radiator circuit.

 

This is high on my list of things "to-do" as we do a lot of winter cruising (liveaboards).

[Chalky]

I seem to remember a boat in the magazines about 10 years ago that was owned by someone from an F1 team and had storage heaters. The ballast was on insulation and a secondary engine cooling circuit ran through it. When needed the coolant was run through the secondary circuit and then to the skin tank to cool it further if required. Theoretically it should work quite well however I would have concerns over the ability of a coolant pump to cope with the extra load.

[Guest]

I have often thought that "Sea Otter" style water-filled ballast tanks could be fitted under the floor, which in turn could be indirectly heated by the waste heat from the engine. That would store a fair amount of heat, but the tank would need insulating from the bottom plate.

[John V]

trouble with a lot of these odd ball ideas is that though they may work, the results are rarely worth the effort.

the other thing is that as they are usually complex, if they go wrong it is often impossible for anyone, apart from the original constructor, to put right.

[blackrose]

Back boiler on fire tied into radiators cheapest heating system as "free" heat when fire is on. Good boat insulation and a means to switch eberspatcher on from Bed total luxury.

 

How does a backboiler produce free heat?

 

You don't get any extra heat from a backboiler. It consumers extra energy to heat the water in a backboiler in the first place, and then all it does is distribute the heat through the boat. You don't get that heat in the radiators for free - unless you found the fuel to heat the water!

 

I take your point but I was just thinking about "free" heat.... to try and reduce running/living costs....longer term, money is going to become less available ;-)

 

In that case forget the eberspacher - having owned one for a few years in my opinion they're a load of crap and not worth the money.

 

They may be ok for people who don't live on their boats and some people think the air blown eberspachers are ok for smaller boats, but if you must have a diesel heater (water circulating) then I think webastos are probably better as they are more user-serviceable.

Edited May 3, 2014 by blackrose

[dmr]

This idea is not "off the wall" and has some potential. The biggest issue is to decide if the heat gained would be worth the expense of Developing and installing such a system, and I used a capital D for emphasis!

 

We and quite a few other boaters already have a system that provides some storage heat. A big engine in a proper engine room next to a bed in the back cabin. In the winter we usually do a battery charge run between 6pm and 8pm and the engine is still helping to keep the back cabin warm till about midnight.

I reckon it would be quite difficult to store enough heat till the next morning but its worth looking at.

Extracting heat from the cooling system and using the 3kW or so that is available from a Travelpower is probably the way to go and has the advantage that it keeps the engine working harder whilst battery charging. There's quite a bit of new research going on into this area so maybe in 10 years time it will be an off the shelf item.

 

...............Dave

 

 

edited for speeling erors.

Edited May 3, 2014 by dmr

[sueb]

I hope you don't get an eperspacher. I used to get very fed up with being woken when a neighbours started in the morning

[blackrose]

I hope you don't get an eperspacher. I used to get very fed up with being woken when a neighbours started in the morning

 

But you don't have to worry about that sort of thing any more do you? From memory, nuisance neighbours can be a lot more annoying in houses and flats.

[kevinl]

 

But you don't have to worry about that sort of thing any more do you? From memory, nuisance neighbours can be a lot more annoying in houses and flats.

I'm no friend of sueb's, never met her but that's just uncalled for.

I still think my mate had the best idea, surround the fire with thermal blocks, they then store heat which they release when the temperature drops below theirs. Dirt cheap, zero moving parts, does not require you to use the engine. As long as the fire is lit they take up heat that would be dissipated otherwise. No pipes, pumps or bugger all just stored latent heat costs about £20, what's the worse that could happen?

K

[John V]

 

I still think my mate had the best idea, surround the fire with thermal blocks, they then store heat which they release when the temperature drops below theirs. Dirt cheap, zero moving parts, does not require you to use the engine. As long as the fire is lit they take up heat that would be dissipated otherwise. No pipes, pumps or bugger all just stored latent heat costs about £20, what's the worse that could happen?

K

 

You arrive on board after being away for a couple of days to a freezing cold boat, you light up the stove and sit there for hours freezing 'cos the "nasty" heat store is stealing half your heat output

 

edited to beat the mods

Edited May 4, 2014 by John V

[Bobbybass]

But your free heat won't be free!

 

No....it won't..

 

It will take extra fuel...

 

Put extra load on the engine...alternator...batteries...and hasten the day when you have to spend £6000 on a new engine !!

 

There is never a free lunch...

 

Generating electric heat of any kind on a boat..is a non-starter.

[John V]

 

No....it won't..

 

It will take extra fuel...

 

Put extra load on the engine...alternator...batteries...and hasten the day when you have to spend £6000 on a new engine !!

 

There is never a free lunch...

 

Generating electric heat of any kind on a boat..is a non-starter.

 

does that include a gearbox? where does your supplier live? or was that just the installation charge?

[dmr]

 

No....it won't..

 

It will take extra fuel...

 

Put extra load on the engine...alternator...batteries...and hasten the day when you have to spend £6000 on a new engine !!

 

There is never a free lunch...

 

Generating electric heat of any kind on a boat..is a non-starter.

 

Not strictly true???? Diesels like to work and are much more likely to suffer from running on light load, so if you are running just to charge batteries or make hot water it actually makes sense to find a way to work the engine harder. And just idling an engine uses a ,lot of fuel so using just a little more to do something useful is very cost effective!

 

..............Dave

[Robbo]

I seem to remember a boat in the magazines about 10 years ago that was owned by someone from an F1 team and had storage heaters. The ballast was on insulation and a secondary engine cooling circuit ran through it. When needed the coolant was run through the secondary circuit and then to the skin tank to cool it further if required. Theoretically it should work quite well however I would have concerns over the ability of a coolant pump to cope with the extra load.

Coolant pumps are Centrifugal, so more pipe work or rads won't put any load on the pump, it will slow the flow down thou due to the extra restrictions.

 

No....it won't..

 

It will take extra fuel...

 

.

Why disagree with NC and then confirm her statement?

[Guest]

Coolant pumps are Centrifugal, so more pipe work or rads won't put any load on the pump, it will slow the flow down thou due to the extra restrictions.

 

Why disagree with NC and then confirm her statement?

I didn't believe he was disagreeing. I took "No...it won't" as an agreement.

[Chalky]

Coolant pumps are Centrifugal, so more pipe work or rads won't put any load on the pump, it will slow the flow down thou due to the extra restrictions.

 

 

I contacted HMI marine about using the coolant pump on our engine to run a couple of rads and was told quite explicitly that the pump would not deliver the pressure to run a circuit of more than 3m. I ended up installing a plate heat exchanger and secondary pump to drive the circuit. The danger is putting the pump into stall so it doesn't move the coolant at a fast enough rate and you end up with localised hot spots in the head.

[Guest]

 

I contacted HMI marine about using the coolant pump on our engine to run a couple of rads and was told quite explicitly that the pump would not deliver the pressure to run a circuit of more than 3m. I ended up installing a plate heat exchanger and secondary pump to drive the circuit. The danger is putting the pump into stall so it doesn't move the coolant at a fast enough rate and you end up with localised hot spots in the head.

You have just frightened me the circs from my Vetus cylinder head are way over 3m! It is piped in 22mm copper though so I think this has helped.